Rtp and Tus DNA Binding

Replication Termination Proteins
Rtp and Tus These polar fork bocking sites have been found in yeast, pea, frog and human genomes.

RTP
RTP is a DNA binding protein from Bacillus Subtilis that uses a helix-loop-helix binding motif. In solution it shows a symmetric structure typical of the winged helix loop helix family, with an unstructured N-terminus end, first alpha helix (a1), unstructured loop that is equivalent to the first beta sheet (B1) , helix loop helix structure (a2 -a3 ), 2 beta sheets with a connecting loop that makes up the 'wing' structure (B2 - B3) and an additional long alpha helix involved in dimerisation (a4).

Assymmetry of RTP in DNA-binding

Wing-up : Contacts upstream with rtp dimer bound to A-site

Wing-down : Contacts with phosphate backbone of downstream DNA

Residues binding to DNA

